Elixir Testing: Stubbing External Dependencies Using Mox

Integration tests often become slow, brittle, and expensive when they rely on real external services or databases. Learning to manage these dependencies is crucial for maintaining a fast development and deployment pipeline. This course teaches you how to effectively use the powerful Mox library alongside ExUnit to create isolated, reliable, and fast integration tests, allowing you to simulate complex external behaviors without connecting to real systems. What you'll learn: * Configure the Elixir testing environment using ExUnit and seamlessly integrate the Mox library. * Understand how to define explicit contracts for external services using Elixir behavior modules and interface definitions. * Practice creating stubs and mocks using Mox to simulate responses and failures from third-party APIs and services. * Apply correct concurrency and isolation strategies to ensure tests run reliably without interfering with each other's state. * Build robust test suites by leveraging basic concepts of property-based testing to validate interface behaviors across diverse inputs. We start with core testing terminology and setup, move into defining clear interfaces using behaviors, and then apply Mox through practical, hands-on examples that demonstrate stubbing complex dependencies. This course is perfect for beginner and intermediate Elixir developers who want to improve the speed and reliability of their application testing. No prior experience with Mox is required, only basic familiarity with Elixir syntax. Start building faster, more dependable Elixir test suites today.